Transparent Cells Offer a Range of Possibilities for Solar Power

Research into photovoltaic (PV) technology, like all renewables, is always striving for greater efficiencies and lower production costs. That quest often creates seemingly unimaginable possibilities. For example, consider solar glass with a view. While it may sound a little far-fetched, one recent breakthrough could give new meaning to the concept of power windows.

In July, researchers at the University of California, Los Angeles (UCLA), announced they had developed a transparent solar cell that, when installed on windows in homes and buildings, could generate electricity while still allowing occupants to see through to the outside.

The advancement was made possible through the use of a new kind of polymer solar cell (PSC) that produces energy by absorbing mainly infrared light, as opposed to visible light. The cell is nearly 70 percent invisible to the human eye.

Polymer cells are distinct from most PV cells that use silicon crystal. The latter are complex in their construction and very expensive. PSCs, on the other hand, are lightweight, flexible, disposable and much less expensive to produce. Because of these qualities, they offer a range of possibilities for thin-film solar applications, such as fabric, portable charging and windows. As a result, the technology has recently attracted increased attention and research. However, they have not yet reached the level of efficiency traditional solar cells enjoy, which has so far kept them out of commercial production.

The UCLA researchers achieved their breakthrough by incorporating near-infrared light-sensitive polymers with silver nanowires to create a transparent electrode.

While the product my not be ready for mass markets, the potential is there. UCLA professor of materials science and engineering Yang Yang, who was the leader of the team that conducted the study, emphasized that the new cells are made from plastic materials, which are lightweight and flexible. More important, he said, “they can be produced in high volume at low cost.”